main.py

import os
import csv
import time
from datetime import date, timedelta
import pandas as pd

def validate_amount(str: str) -> float:
    """Checks if a string can be converted to valid $ amount (positive float with 2 or less decimals).
       \nIf invalid, asks the user to enter a new string until it is valid.
    """
    while True:
        try:
            float(str)
            if float(str) < 0:
                str = input("Please enter a positive $ amount. ")
                continue
            if ("." in str) and len(str.split(".")[1]) > 2:
                str = input("Please enter a $ amount with 2 or less decimals. $ ")
                continue
            return float(str)
        except ValueError:
            str = input("Please enter a numerical $ amount. $")
            
def validate_date(date_str: str) -> date:
    """Checks that a string is a valid date. If invalid, asks for new input until it is valid.
    Returns a date object."""
    while True:
        try:
            user_date = date.fromisoformat(date_str)
            return user_date
        except ValueError:
            date_str = input("Invalid date, please try again in format YYYY-MM-DD ")

def create_account():
    """Creates a new account with a unique name.\n
    Appends [account_name, starting balance] to the balances.csv file.\n
    Also creates a new account_name.csv file to store transactions.\n
    Catches exceptions in the file handling process."""
    account_name = input("Enter a name for your account: ").upper()
    while (f"{account_name}.csv" in os.listdir("program_files")):
        account_name = input("That account name is not available, please enter another name: ").upper()
    starting_balance = validate_amount(input(f"What is the starting balance of your {account_name} account? $"))

    try:
        with open("program_files/BALANCES.csv", "a", newline="") as balance_csv:
            balance_writer = csv.writer(balance_csv)
            balance_writer.writerow([account_name, starting_balance])
        with open(f"program_files/{account_name}.csv", "x", newline="") as account_csv:
            pass
    except Exception as e:
        print(f"An error occurred. Error message '{e}'. Please try again.")

def make_transaction(account_name: str, amount: float, date: date, category: str, memo: str) -> None:
    """Appends the transaction to the individual account file in the format [date, category, amount, memo] and the all accounts file in the format [account name, date, category, amount, memo].
    Updates the balance file.
    Prints a summary of the transaction and the new account balance."""
    try:
        with open(f"program_files/{account_name}.csv", "a", newline="") as account_csv: # appends the transaction to the individual account file
            transaction_writer = csv.writer(account_csv)
            transaction_writer.writerow([date, category, -amount, memo])

        with open("program_files/ALL ACCOUNTS.csv", "a", newline="") as all_csv: # appends the transaction to the all accounts file
            all_writer = csv.writer(all_csv)
            all_writer.writerow([account_name, date, category, -amount, memo])

        current_balances = [] # updates the balance in the balances file
        this_account_balance = 0
        with open("program_files/BALANCES.csv", "r", newline="") as balances_csv:
            balance_reader = csv.reader(balances_csv)
            for row in balance_reader:
                if row[0] == account_name:
                    this_account_balance = round(float(row[1])-amount,2)
                    current_balances.append([row[0], this_account_balance])
                else:
                    current_balances.append(row)
        with open("program_files/BALANCES.csv", "w", newline="") as balances_csv:
            balance_writer = csv.writer(balances_csv)
            balance_writer.writerows(current_balances)

        if this_account_balance <= 0:
            print(f"\nWarning: your {account_name} account now has a balance of ${float(this_account_balance):.2f} ( • ᴖ • ｡)")
        else:
            print(f"\nYour {account_name} account now has a balance of ${float(this_account_balance):.2f} (˶ᵔ ᵕ ᵔ˶)")

        print(f"\t${float(-amount):.2f} - {category} - {date}")
        time.sleep(1)
    except Exception as e:
        print("An exception occurred. Transaction not recorded. Message: " + str(e))

def search_transaction(start_date: date, end_date: date, account: str) -> None:
    """Prints transactions in the file {account.csv} that have a date that is between {start_date} and {end_date}, inclusive.
    Sorts them by date before printing. Each transaction is formatted [date, category, amount, memo]"""
    print(f"Transactions from {start_date} to {end_date}:")
    try:
        transactions = pd.read_csv(f"program_files/{account}.csv", header=None, parse_dates=[0])
        transactions.columns = ["DATE", "CATEGORY", "AMOUNT", "MEMO"]
        transactions.sort_values(by="DATE", inplace=True)

        in_range = transactions[(transactions["DATE"] >= start_date.isoformat()) & (transactions["DATE"] <= end_date.isoformat())]
        if len(in_range) == 0:
            print("\tNo transactions found.")
        else:
            print(in_range.to_string(index=False))
    except Exception as e:
        print(e)

def display_stats(account_name: str) -> None:
    '''Print the total amount spent for each category of transactions in the 'account_name' account'''
    try:
        transactions = pd.read_csv(f"program_files/{account_name}.csv", header=None, parse_dates=[0])
        transactions.columns = ["DATE", "CATEGORY", "AMOUNT", "MEMO"]

        print(transactions.groupby("CATEGORY", as_index=False)["AMOUNT"].sum())
    except Exception as e:
        print("An exception occurred.")
        print(e)

def menu1():
    print("\n✦ Record a transaction ✦")

    account_name = input("\tWhich account would you like to access? ").upper()
    while (f"{account_name}.csv" not in os.listdir("program_files") or (account_name == "ALL ACCOUNTS") or account_name == "BALANCES"):
        account_name = input("\tAccount not found. Please enter a valid account name, or type 'm' to return to the menu to create an account. ").upper()
        if account_name == "M":
            return
        
    debit_credit = input("Would you like to record a debit or a credit? (d/c) ").lower()
    while (debit_credit != "d" and debit_credit != "c"):
        debit_credit = input("Not a valid choice, please enter 'd' or 'c'. ").lower()

    transaction_amount = validate_amount(input("\tEnter the transaction amount. $"))
    if debit_credit == "c":
        transaction_amount *= -1

    transaction_category = input("\tEnter a category for the transaction. ").upper()
    transaction_memo = input("\tEnter a memo for the transaction (optional) ")
    transaction_date = input("\tEnter the transaction date in the format YYYY-MM-DD (if blank, defaults to today) ")
    if transaction_date == "":
        transaction_date = date.today()
    else:
        transaction_date = validate_date(transaction_date)

    make_transaction(account_name, transaction_amount, transaction_date, transaction_category, transaction_memo)
    print("\nTransaction recorded ( • ᴗ - ) ~ ✧")  

def menu2():
    print("\n✦ Record a transfer ✦")

    account_name = input("\tWhich account would you like to access? ").upper()
    while (f"{account_name}.csv" not in os.listdir("program_files") or (account_name == "ALL ACCOUNTS") or account_name == "BALANCES"):
        account_name = input("\tAccount not found. Please enter a valid account name, or type 'm' to return to the menu to create an account. ").upper()
        if account_name == "M":
            return
    
    transfer_to_name = input("\tWhich account would you like to transfer to? ").upper()
    while (f"{transfer_to_name}.csv" not in os.listdir("program_files") or (transfer_to_name == "ALL ACCOUNTS") or transfer_to_name == "BALANCES"):
        transfer_to_name = input("\tAccount not found. Please enter a valid account name, or type 'm' to return to the menu to create an account. ").upper()
        if transfer_to_name == "M":
            return

    transaction_amount = validate_amount(input("\tEnter the amount to be transferred. $"))
    transaction_memo = input("\tEnter a memo for the transaction (optional) ")
    transaction_date = input("\tEnter the transaction date in the format (if blank, defaults to today) ")
    if transaction_date == "":
        transaction_date = date.today()
    else:
        transaction_date = validate_date(transaction_date)

    make_transaction(account_name, transaction_amount, transaction_date, "TRANSFER TO " + transfer_to_name, transaction_memo)
    make_transaction(transfer_to_name, -transaction_amount, transaction_date, "TRANSFER FROM " + account_name, transaction_memo)

    print("Transfer recorded ( • ᴗ - ) ~ ✧")

def menu3():
    print("\n✦ View transactions ✦")
    print("\t1. This current month")
    print("\t2. The past week")
    print("\t3. From a specific date range")

    menu3_choice = input("Pick which transactions you would like to view (1/2/3) ")
    valid_choices = ["1", "2", "3"]
    while (menu3_choice not in valid_choices):
        menu3_choice = input("Invalid option. Please try again. ")

    account_name = input("\tWhich account would you like to view the transactions from? ").upper()
    while (f"{account_name}.csv" not in os.listdir("program_files") or (account_name == "ALL ACCOUNTS") or account_name == "BALANCES"):
        account_name = input("\tAccount not found. Please enter a valid account name, or type 'm' to return to the menu to create an account. ").upper()
        if account_name == "M":
            return

    date1 = None
    date2 = None
    if menu3_choice == "1":
        date1 = date(date.today().year, date.today().month, 1)
        # sets date1 as the first day of the current month

        date2 = date(date.today().year, date.today().month, 28) + timedelta(4)
        date2 = date2 - timedelta(1)
        # sets date2 as the last day of the current month

    if menu3_choice == "2":
        date2 = date.today()
        date1 = date2 - timedelta(7)

    if menu3_choice == "3":
        date1 = input("\tEnter the starting date in the format YYYY-MM-DD (if blank, defaults to today) ")
        if date1 == "":
            date1 = date.today()
        else:
            date1 = validate_date(date1)
        
        date2 = input("\tEnter the ending date in the format YYYY-MM-DD (if blank, defaults to today) ")
        if date2 == "":
            date2 = date.today()
        else:
            date2 = validate_date(date2)

    search_transaction(date1, date2, account_name)  

    time.sleep(3)

def menu4():
    print("\n✦ View account balances ✦")

    try:
        with open("program_files/BALANCES.csv", "r", newline="") as balances:
            balance_reader = csv.reader(balances)
            for row in balance_reader:
                print(f"\t{row[0]} account has a balance of ${float(row[1]):.2f}")
    except Exception as e:
        print("Exception occurred.")
        print(e)
    time.sleep(1.5)
        
def menu5():
    print("\n✦ Create new account ✦")
    create_account()
    print("Account created ( • ᴗ - ) ~ ✧")

def menu6():
    print("\n✦ Display stats ✦")

    account_name = input("\tWhich account would you like to view the stats for? ").upper()
    while (f"{account_name}.csv" not in os.listdir("program_files") or (account_name == "ALL ACCOUNTS") or account_name == "BALANCES"):
        account_name = input("\tAccount not found. Please enter a valid account name, or type 'm' to return to the menu to create an account. ").upper()
        if account_name == "M":
            return
    print(f"Total spending stats for your {account_name} account:")
    display_stats(account_name)
    time.sleep(2)



#main loop
timeDelay = .4
print("\n⋆˙⟡ Welcome to the Finance Tracker ⟡˙⋆\n")

try:
    with open("program_files/ALL ACCOUNTS.csv", "a", newline="") as all_csv:
        pass
    with open("program_files/BALANCES.csv", "a", newline="") as all_csv:
        pass
except FileNotFoundError:
    os.mkdir("program_files")
    try:
        with open("program_files/ALL ACCOUNTS.csv", "a", newline="") as all_csv:
            pass
        with open("program_files/BALANCES.csv", "a", newline="") as all_csv:
            pass
    except Exception as e:
        print("There was an exception. Please check that there is a program_files folder.")
        print(e)

menu_control = ""
while True:
    time.sleep(timeDelay)
    print("⋆ Main Menu ⋆")
    print("\t1. Record transaction (debit/credit)")
    print("\t2. Record transfer between accounts")
    print("\t3. View transactions")
    print("\t4. View account balances")
    print("\t5. Create new account")
    print("\t6. Display stats")

    time.sleep(timeDelay)
    menu_control = input("\nSelect a menu option (1, 2, 3, etc.) or type 'quit'\n")

    if menu_control.lower() == "quit":
        break
    
    if menu_control == "1":
        menu1()
    elif menu_control == "2":
        menu2()
    elif menu_control == "3":
        menu3()
    elif menu_control == "4":
        menu4()
    elif menu_control == "5":
        menu5()
    elif menu_control == "6":
        menu6()
    else:
        time.sleep(timeDelay)
        print("\nInvalid input. Please enter a number from the menu.")
    print("")
    time.sleep(timeDelay)